The Effect of DC Discharge on the Properties and Surface Structure of Polyphenylene Oxide Films

Abstract—The effect of low-pressure direct current discharge on polyphenylene oxide films was studied. Filtered atmospheric air was used as the working gas. It was shown that plasma treatment leads to significant hydrophilization of the polymer surface during treatment at the cathode and anode. The storage of modified films in air leads to a decrease in hydrophilicity, which is more characteristic of films treated at the anode. The change in the chemical structure of plasma-modified samples was studied by X-ray photoelectron spectroscopy and the formation of a significant amount of oxygen-containing groups was shown during plasma treatment of films. The atomic content of oxygen increased to a greater extent after treatment at the anode. Using atomic force microscopy, the change in film morphology after exposure by plasma was studied and a significant increase in their roughness was established. The modified films had significantly higher selectivity of gas permeability for CO2/CH4, CO2/N2 and O2/N2 vapors without reducing the flow of CO2 and O2 relative to the initial values.